"and the option to pay a small fee of Crowns to get a second chance at a boss drops after defeating the boss."

That crosses a line that I at least am uncomfortable with. These games are already obfuscated slot machines without the developers introducing such a transparent mechanic. Aside from any question of what this means for "balance," does this strike any of you as problematic for a game pitched to a younger audience?

One might draw the analogy to boosters in TCG's, which I also dislike, but in the present case the items are even more ephemeral in value and the "micro" transactions small enough such that it might reinforce an impulsive, gambling response.